John a



(No Model.)

J. A. CALDWELL.

ELLIPSOGRAPH.

Patented Dec. 11, 1894.

WITNESSES:

Mal/a1 .wa

- A TTOHNEYS.

UNITED STATES PATENT OFFICE.

JOHN A. CALDWELL, F VANCOUVER, CANADA.

EILLIPS'OGRARPH.

SPECIFICATION forming part of Letters 1 atent'No.530,8 22, dated December 11, 1 894. Application filed M aroh 26.1894. seem... 605,110. on. models To all whom it may concern.-

Be it known that LJOHN A. CALDWELL, of Vancouver, British Columbia, Canada; have invented a new and Improve'd Ellipsograph,= of which the following is a full, clear, and exact description.

The invention relates to drawing instruments, and its object is to provide anewand improved ellipsograph,'whichis simpleand" durable in construction, very eflective' in op-" eration, and arranged to permit the'operat'or to draw almost any kind of an ellipse.

Theinvention consists principally of acom pass, a sleeve fitted to slide loosely'onone of the legs of the compass, and arod heldadjustable in the said sleeveand standing at right angles to the leg carrying the sleeve, the said rod supporting the pencil or pen.

The invention also consists of certain parts and details, and combinations of the-same, as will be hereinafter described and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, inwhich similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a perspective View of the improvement. Fig. 2 is a side elevation of an extension leg. 'Fig. 3 is an end elevation of the pen holder. Fig. 4 is a side elevation of the same; and Fig. 5 is an enlarged sectional side elevation of a modified form of slide for the compass legs. Theiniproved ellipsograph is provided with a compass having the legs A and B connected together by the pivot O in the usual manner. On the leg A of the compass is held adjustable a sleeve D adapted to be fastened in place on the leg by a set screw E, and on the said sleeve is pivoted an arm F provided with a transversely-extending foot G having points adapted to engage the drawing board or other place on which the ellipse is to be drawn. The arm F with its foot G serves to adjust and to hold the compass in a vertical position. The center point G of the foot G is used to bring the legs A and B plumb, or to a true vertical position, that is when the legs A B and point G are in the same vertical plane. On the leg B of the compass is fitted to slide loosely a sleeve H carrying a .rod I adapted to be adjusted in the said sleeve,

.set screw H .arm I stands at right angles to th'eleg' B and onone end thereof is held a holder J :adapted to be fast'enedin place on'the rod I byaset screw The holder J stands at.

\ in Fig. 5, that is,

and fastened in screwing in the sleeve.

place after adjustment by a right angles'totherod I andparallel to the leg B and is adapted to support a pencil L, as shown in Fig. l or adapted to receive a pen holder illustrated in Figs. 3 and 4'. This pen-holder is provided with a rod N heldad' justable in the holder J and adapted to be fastened therein by a set-screw O, as shown :in- Figs. 3 and 4.

On'thelower end of the rod N ispivoted a support Pcarrying the pen Q and on-the said support is held adjust'able'a pin R adapted to be fastened in place by a set screw R screwingin thesupport P, the said pin serving: to hold the pen Q at all times inproper relative position to the paper or other article or material on which the ellipse is to be drawn. For drawing very large ellipses, I prefer to make the slide H in the shape shown beam which is to the beam being fastened in place by the set screw H. Now, in order to draw an ellipse the operator first adjusts the compass in such This form it with abearing for a take the place of the red I,

a manner that the point of the leg B is in the center of the ellipse to be drawn, with the other leg A having its point in the major axis of the ellipse as plainly indicated in Fig. 1. The operator now turns the sleeve H and adjusts the rod I in the said sleeve until the pencil L or pen Q engages the minor axis ofthe ellipse at the outermost point of the said minor axis, and then the operator fastens the rod I in place on the sleeve H and then swings the latter around and moves the leg A forward or backward on the major axis until the point of the pencil L or pen Q touches the outermost point of the ellipse on the major axis. The operator then brings the legs A and B to a vertical position by engaging the foot G with the drawing board and with its center 'point on the major axis, and so by fastening the sleeve D holding the legs A and B vertical. The operator can now draw onehalf of the ellipse from one side of the minor ICO up and down on the leg according to the movement of the point of the pen or pencil on the paper. When this has been done the operator swings the legA to the other side of the ellipse to again engage the major axis thereof and then the above described operation is repeated, that is, the other half of the ellipse is drawn in the manner described. Thus, it will be seen that by adjusting the legs A and B on the major axis and the rod I so as to bring the point of the pen or pencil on the extreme point on the minor axis of the ellipse, any desired ellipse may be drawn.

Having thus fully described my invention, I claim as new and desire to secure by Letters Patent- 1. An ellipsograph, comprising a compass, a sleeve fitted to slide loosely on one of the legs of the compass, and a rod held adjustable in the said sleeve and standing at right angles to the leg, the said rod carrying apenoil or pen-holder, substantially as shown and described.

2. An ellipsograph, comprising a compass,

a device for adjusting to and holding the compass in a vertical position, a sleeve fitted to slide loosely on one of the legs of the compass, and a rod held adjustable in the said sleeve and adapted to be fastened thereto, the said rod standing at right angles to the leg carrying the said sleeve, the said rod also carrying a pencil or pen-holder, substantially as shown and described.

3. An ellipsograph, comprisinga verticallydisposed compass, a sleeve fitted to slide loosely on one of the legs of the compass, a

rod held adjustable in the said sleeve and standing at right angles to the leg carrying the sleeve, and a holder held adjustable on the said rod and adapted to carry a pen or pencil, substantially as shown and described.

4. An ellipsograph, comprising a sleeve fitted to slide loosely on one of the legs of a compass, a rod held adjustable in the said sleeve and standing at right angles to the leg carrying the sleeve, and a holder held on the said rod and adapted to carry a pen or pencil, the said holder standing at right angles to the rod substantially as shown and described.

5. An ellipsograph, comprising a sleeve fitted to slide loosely on one of the legs of the compass, a rod held adjustable in the said sleeve and standing at right angles to the leg carrying the sleeve, a holder held on the said rod, a second rod held adjustable in the said holder, and a pen support pivoted 011 the said second rod, substantially as shown and described.

6. An ellipsograph, comprisinga sleeve fitted to slide loosely on one of the legs of the compass, a rod held adjustable in the said sleeve and standing at right angles to the leg carrying the sleeve, a holder held on the said rod, a second rod held adjustable in the said holder, a pen support pivoted on the said second rod, and a pin held adj ustable on the pivoted support, substantially as shown and described.

JOHN A. CALDWVELL.

Witnesses:

IVAN BUSHONG, EDWARD J. ARTHUR. 

